1. Field of the Invention
The present invention relates to a display apparatus and a control method thereof. More particularly, the present invention relates to a display apparatus and a control method thereof, which reduces the time taken to stabilize the brightness when initially driving a display apparatus and which displays a stable and high-quality picture.
2. Description of the Related Art
In general, a display apparatus with a liquid crystal (LCD) panel comprises a backlight unit to illuminate the LCD panel, an inverter to drive the backlight unit, and a power supply to supply power to the inverter. In the conventional display apparatus, the brightness of the LCD panel is varied as the backlight unit is driven when the power is initially supplied, a phenomena which is described in greater detail below with reference to FIG. 1A.
While initially supplying the power, the power supply supplies a normal voltage to the inverter so as to drive the backlight unit. Thus, the inverter receives the normal voltage and drives the backlight unit such that the brightness of the LCD panel gradually increases and approximately reaches normal brightness (about 90%) after a lapse of a time t1.
However, the conventional display apparatus has a disadvantage in that the time t1 taken to reach normal brightness is relatively long.
A conventional display apparatus for overcoming this disadvantage is described in greater detail below with reference to FIG. 11B. In this conventional display apparatus, the power supply supplies an overvoltage to the inverter when the power is initially supplied such that the brightness of the LCD panel reaches normal brightness after a lapse of a shorter time t2. Then, when the temperature of the backlight unit reaches a predetermined temperature at a time t2′, the power supply supplies the normal voltage to the inverter. However, in this case the brightness of the LCD panel rapidly increases until the time t2′ and then suddenly returns to the normal brightness due to voltage variation (that is, the variation from the overvoltage returning to the normal voltage).
Thus, in the foregoing display apparatus, when the power is initially supplied to drive the backlight unit, the brightness of the LCD panel is suddenly changed after the lapse of the time t2′ such that the LCD panel blinks and provides a user with a low quality picture.
Accordingly, a need exists for a system and method for reducing the time taken to stabilize the brightness and display a high-quality picture in a display apparatus.